Is she on painkillers? Bunnies don’t handle pain well at all. I would definitely talk to the vet about it when you go in tomorrow.
When I adopted by two little buns, they were both very sick (major GI Stasis) at first I thought it was just stress from the move, but by the end of the first day I rushed them to the vet. It took them a very long time to heal completely. I was also not very good at getting them to take their critical care as they fought me SO much. I took them in to the vet a couple times to have them help me feed them and it took three of us. A few days later, we went back and put them on motility drugs and painkillers. They perked up a few days after they’d been taken the pain killers. It still took weeks to get them to start eating normally and they still don’t drink nearly enough water for my liking, but their energy is good and they’re eating lots of water soaked veg and hay.
As for vets veggy recommendations. Yes and no. You definitely want them to be getting lots of water to help keep things moving, but you also don’t want to give them diarrhea when they’re not taking in enough nutrients as it is. Your vet is just being cautious as some buns have very sensitive tummies. I don’t know about unlimited pellets though… I’ve heard lots of people who have their bunnies on that type of diet and have no problems, but my vet said (accurately I believe) that pellets aren’t really that high in nutrients, but are very high in calories. Are you able to get Fluffy to eat hay? You want her to be eating that if possible. Critical care is supposed to be high in everything they need so if you’re able to get that into her, she’s at least getting food. If she’s not drinking any water, try syringing some into her mouth as well.
As for how long they can be in stasis. Full stasis, not very long. It sounds like Fluffy has a bit of movement though so that’s promising. I don’t know how long my little guys were sick before I got them, but I have a feeling it was a long time based on what the lady told me in regards to how often she had to clean their litterbox. And it was at least a month after I started treating them that their bowels are starting to function normally.
Anyway. Painkillers, painkillers. Painkillers! You should notice a difference in at least Fluffy’s mood after a few treatments.